Step-ladder



(No Model.)

H. R. SMITH.

STEP LADDER.

No. 304.466. Patented Sept. 2, 1884'l y JVOQM UN rTnn- STATESA PATENT @Trient HARRY R. SMITH, OF BANGOR, MAINE.

STEP-LADDER.

SPECIFICATION forming part of Letters Patent No. 304,466, dated September 2, 1884.

Application filed June 16, 1884. (No model.) d

To all whom t may concern,.- y

Be it known that I, HARRY R. SMITH, a citizen of the United States, residing at Bangor, in the county of Penobscot and State of Maine, have invented certain new and useful Improvements in Ladders, of which the following is a specication.

My invention is a step-ladder as fully described hereinafter, so as to secure great strength and rigidity and afirm connection of the parts together.

In the drawings, Figure l is a side view of a step-ladder having my improvements. Fig. 2 is an enlarged section on the line l 2, Fig. l. Figs. 3 and 4 are detached perspective views of one of the brackets and plates. an enlarged section on the line 3 4, Fig. l. Fig. 6 is ancnlarged section on the line 5 6, Fig. l. Fig. 7 is a perspective view of one of the step-brackets.

The ladder consists of the side pieces, steps, top board, bracing-strips, and the connections hereinafter set forth. rlhe side pieces, A, instead of consisting of a single strip of nia terial, consist each of a thin straight strip, a, and heavier arched or curved strip, I), the two strips, when secured together, as shown, constituting a truss of the usual construction. The top board, B, is connected with each side piece and with the adjacent brace-strip C by the metal bracket D. Each bracket is formed,

preferably, in one piece,with a side ilange or plate, d, cut away in any suitable manner-to reduce the weight, top llange, f, and brackets or buttressesl t' t" i?, which extend from the side tothe top ilange, as shown. The space between the buttresses t' t and side d constitutes a socket adapted to receive the upper end of the side piece, A, which its snugly therein, andl is thus braced, so that it can be most effectually secured by means of screws passed through openings u in the bracket. the side piece consists of more than one strip, the-pieces are reta-ined in relative position in and by the socket, so that the structure is braced and strengthened, while it is unnecessary to perforate and weaken the side piece to receive nails or bolts passing from front to rear.

To theupper end of each brace C is secured a plate, E, preferably formed with side flanges g f/ to receive between them the brace and aid constructed,

Fig. 5 is in retaining the plate in its place, so that it maybe securely held by screws passed through openings y in the plate. vided with a circular projection, h, at the i11- ner side adapted to a circular opening, x, in the side d of the bracket, and with a curved bearingedge, yzo, adapted to bear upon the curved edge t of the bracket, the curved bearing-edges w t coinciding with parts of circles, the center of which is the center of the opening x and projection h. rlhe plateE is placed against the outside of the ange d with the projection 7L in the opening fr, and the braceC is placed between the flanges g g and against the inside of the iiange d, and a screw, o, is passed through an opening at the center of the proj eetion L, so as to draw the plateE and .brace together to clamp the lange d between them, and thus hold the brace to the bracket with such friction that while it can be moved to any desired .position it will not swing loosely at any time. or weight of the ladder is sustained by the bearings formed by the edges w t, and the projection h and recess x, so that there is little or no strain upon the screw o. The flange d is provided with shoulders r 1"', which limit the swing of the plate E and the movement of the brace G. The brackets are secured to the top board,B,by screws passed through openings Z in the flanges f.

To prevent the spreading apart of the side pieces, A A, and the loosening of the treads or steps J, and to further secure additional bearings for the latter and brace the structure, I use T-brackets F, each consisting of a stem, m, perforated to receive screws or to be otherwise attached to the 'under side of a step, and of a cross-bar, n,which has a sharp inner edge, q. Each bracket F is placed in the position shown 'in Fig. 6 with its stem between the strips a b and driven in until its sharp edge q has penetrated the outer sides of the strips and has a firm hold thereon, and the step is then put in place and secured to the stem-m, when the side piece will be firmly clamped to the step, the latter securely supported in its place, and the whole structure is braced and. prevented from twisting, and this is effected without boring or perforating and weakening the side strips, as is necessary when the steps are supported by nails driven through said It will be seen that the strain'A The plate E is pro- 5 IOO strips, or by a connecting-piece provided with nails cast with it and passing through the side strips as heretofore.

It will be evident that the brackets F may be connected to the steps in any suitable manner, and that the brackets D may be differently v formed, provided there are flanges d with sockets for the side pieces and recesses for the projections 71,. It Will also be evident that the projections h may be on the side pieces, d, and the recesses m in platesE.

The buttress i2 may in some cases be dispensed With,as may the bearings t w upon the bracket and plate. A

Vithout limiting myself to the precise construction and arrangement of parts shown, I claim- 1. The combination, in a ladder7 of side pieces consisting of strips a b, steps and T- shaped brackets secured to the steps, and having cross-pieces with edges penetrating the outer faces of the side strips, substantially as described.

2. The combination of the side pieces consisting of strips a b, and brackets having side flanges, d, and buttresses z' t, receiving and clamping together between them the ends of said strips a. b of the side pieces, substantially as described.

3. The combination of the top board and brackets D,provided with side iianges, d, and

recesses w, and the braces C, provided with plates E, having circular projections' adapted to said recesses, substantially as described.

4. The combination of the bracket D, secured to the topboard, and provided with a recessed side flange, and the plate E,having a projection adapted to said recess, and the brace C, the ilange d being clamped between the brace and the plate, substantially as described.

5. The combination of the bracket having a recess,x, and curved edge t and shoulders r r', and the plate E, having a projection adapted to said recess and a curved bearing, fw, andthe brace C, between which and the plate the side of the bracket is clamped, substantially as de scribed.

, 6. The bracket D,adapted for attachment to the top board of a ladder, and having anges df and buttresses t' i, and recess x, and bearing-edge t, in combination with the plate E, adapted for attachment to the brace, andhav- `ing a circular projection, h, and bearing w,

and :flanges g g, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.Y

HARRY n. SMITH.

Vitnesses:

C. E. BLACK, H. AUKWARD. 

